Apparatus for extracting starch and gluten from a
dough op wheat flour

ABSTRACT

AN APPARATUS FOR SEPARATING STARCH FROM AND COLLECTING GLUTEN IN A TREATING ZONE BY REPEATEDLY CATCHING AND PUSHING THE GLUTEN IN THE ZONE, LIFTING THE LUMPS OF COLLECTED GLUTEN OUT OF THE ZONE, AND DROPPING THE LUMPS OF GLUTEN BACK TO THE TREATMENT ZONE IN AN OPTIONALLY REPEATED SERIES AS BY MEANS OF IMPROVED ARRANGEMENTS AND FORMS OF DIFFERENT PLURALITIES OF SPECIAL TREATMENT AND WORKING MEMBERS WITHIN A TANK-SUPPORTED PERFORATED TROUGH INTO WHICH A WASHING LIQUID IS DIFFUSED AND QUICKLY DRAINED AWAY.

June 20, 1972 PLAVEN Re. 27,402

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APPARATUS FOR EXTRACTING STARCH AND GLUTEN FROM A DOUGH OF WHEAT FLOUR Original Filed July 30, 1965 I5 Sheets-Sheet 5 4am WM4/M United States Patent Ofiice Re. 27,402 Reissued June 20, 1972 27,402 APPARATUS FOR EXTRACTING STARCH AND GLUTEN FROM A DOUGH OF WHEAT FLOUR Erik Plaven, Scheelegatan 1, Stockholm, Sweden Original No. 3,506,485, dated Apr. 14, 1970, Ser. No. 476,128, July 30, 1965. Application for reissue May 15, 1970, Ser. No. 37,578 Claims priority, appligationfiiweden, Aug. 4, 1964,

4 Int. Cl. B03b 3/ 00, 11/00; C131 1/00 US. Cl. 127-25 Claims Matter enclosed in heavy brackets II] appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE This invention relates to a process and apparatus for extracting starch and gluten from a dough of wheat flour and water in which the dough is treated with a wash liquid which catches the starch and carries it out of the treatment zone and in which the gluten forms into lumps, and more particularly to the apparatus for carrying out this process of the type consisting of a trough having a semicircular, at least partly perforated bottom, treatment means fastened to a rotating shaft arranged lengthwise in the trough, and devices for the addition of wash water and discharge of this water together with extracted starch via the perforations, the dough being introduced at one end of the trough and the gluten being discharged at the other end. In the methods and apparatus as hitherto known for extracting starch and gluten from a dough of wheat flour, it has been necessary to use a high-quality flour, but in spite of the high flour quality it has not been possible to obtain a high yield and quality of the products without incorporating a lengthy and labour consuming and thus rather costly treatment. The extraction process suggested by the present invention makes it possible to reduce the treatment time considerably also when using a low-grade flour, whereby labour is required for supervision only. The process according to the invention is characterized by the steps of collecting the gluten by catching and pushing it through the treatment zone, whereby small gluten particles or gluten lumps present in the zone and not caught stick to and are absorbed by the gluten or gluten lumps pushed through the treatment zone, and causing the wash liquid added to discharge from the treatment zone without forming any noticeable liquor level.

The apparatus for carrying out the process outlined above is characterized by the fact that the treatment means are in the form of stirring rods [or] sabre-like blades and scrapers and that the trough is perforated substantially throughout the extension of the sections where the trough is concentric with the shaft of the scrapers and thus broadly parallel with the paths of rotation of the rods and the scrapers, all in order that the scrapers or sabres during their rotation in the trough and around the shaft may catch and cut gluten and gluten lumps and carry the-m through the trough in the transverse direction thereof, and may lift the gluten lumps out of the trough at one side thereof and let them fall back into the trough at the other side thereof, and that water supplied to the trough may be discharged through the perforations without causing any essential water accumulation in the trough.

The invention is described below, reference being made to the accompanying drawings, in which:

FIG. 1 shows a longitudinal section of a trough according to the invention.

FIG. 2 shows a cross section of the trough.

FIG. 3 shows a perspective view from above of the greater part of the trough.

The rotating main shaft 1 of the apparatus, shown in the drawings, for extracting starch and gluten by treatment of dough with liquid has treatment means, generally designated 2, fastened to it for working and transporting the dough crosswise and lengthwise along the wholly or part- 1y perforated bottom of the trough 3. For forming the dough, wheat flour is mixed with water and worked to a plastic but still firm dough, which thereafter, possibly after a certain swelling time in a tank 4, is introduced through an opening 5 into the supply end 6 of the trough. The gluten separated off from the dough during the treatment in the trough 3 is discharged through the discharge end 7 of the trough. During the treatment or washing in the trough 3 the dough is sprayed with water or socalled starch milk, i.e. water which has already been used one or more times for washing the dough in the trough 3 or possibly in following washing devices. This liquid is introduced through spray pipes 8, 9, 10 and 11 into the top part of the trough. The liquid is fed to the spray pipes 8-11 through pipes 12 and pump means 28 incorporated with said pipes 12. The wash liquid with suspended starch is discharged from the trough 3 via collectors 30 through pipes 13 and pump means 29 incorporated with said pipes 13 to devices (not shown) for separating starch from the wash liquid. The pipe 13 from the trough section sprayed by the spray pipe 11 may be connected to the spray pipe 10, and the pipe 13 from the trough section sprayed by the spray pipe 10 may be connected to the spray pipe 9, etc. By this arrangement the amount of water needed is reduced and the small gluten particles, possibly passed through the perforation and carried by the wash liquid, are returned to the treatment compartment of the trough 3. The use of starch milk in this way as wash liquid has not previously been possible in the earlier stages of the dough washing process, especially not when low-grade flour has been used.

The trough 3 is perforated practically throughout the length of the sections 14, which are concentric with the shaft 1, and thus mainly in parallel with the path of rotation of the treatment means 2. The treatment means 2 are in the form of rods, [or] scraper blades, and sabrelike blades, with the ends or edges turned towards the sections 14. The trough 3, with the exception of its very beginning at the feed end where it [should] may suitably be imperforate, is perforated substantially throughout its length but only in sections 14 mentioned where the trough is concentric with the shaft 1. In other words, the vertical sides 15 of the trough 3 as shown in the figures are imperforate, as on these vertical sections perforations would not alfect the treatment at all. As the shaft 1 and thus also the treatment means 2 always rotate in the same direction, the treatment will mainly take place in that part of the trough where the treatment means 2 move from their lowest point and upwards. Consequently, the perforations might be limited to only this section of the trough. Further, for the utilization of the invention the trough 3 need not be perforated in its full length between the feed end 6 and the discharge end 7, but it may be suitable to let perforated sections 14 alternate with imperforate sections 16 as shown in the figures.

The treatment means 2 are somewhat different in shape r securing the best possible treatment of the dough and 1e gluten from which more or less starch has been :parated. Common to all treatment means 2 is, however, at they project close to the semicircular parts of the actions 14 and 16. At the feed end 6 of the trough 3, here the trough [is] may be imperforate, the main task E the treatment means 2 is to tear and divide the dough, I stir it and to make it possible for the wash Water D reach the dough on as large contact surfaces as posble in order to flush off the starch. Therefore, at the ed end 6 the treatment means 2 have the shape of irring rods 17 fixed radially to the shaft 1. In the per- )rated sections 14 of the trough 3 at least part of the eatment means 2 are in the shape of scrapers or transfer .eans 18, the blades of which are mainly .parallel with ad radial to the shaft 1. The length of the blades in their [tension parallel with the shaft 1 corresponds mainly a the extension of the section 14 in the same direction. or practical reasons se'veral scrapers and sabres are armged along the shaft to cover the full length of the (tension of the perforated section parallel with the shaft. 1 their rotation in the direction shown by the arrow 20 L FIG. 3 the scrapers 18 catch gluten lumps and push rem along the curve of the perforated plate and lift them ntil they fall down back onto the trough bottom. Durlg the treatment the gluten lumps are caught several mes by the scrapers 18, lifted and returned to the botm of the trough 3, simultaneously also being slowly )nveyed towards the discharge end 7 of the trough 3 1e to the scraper blades not being fully parallel with re shaft 1. When the gluten lumps are pushed along the lrve of the perforated blades, they absorb gluten parcles which are too small to be caught bythe scraper lades and such particles as are sticking in the perforaons. Through this action the perforations are kept open that the wash liquid can discharge without accumulatig in the treatment area. It is very important that the ash liquid should be drained off continuously from the :rforated trough plate, for if the gluten lumps pushed ong the curve of the screen plate are submerged in ater, they will not have sufficient absorption power to itch and merge With the small gluten particles sticking the perforations or suspended in the wash liquid.

The action of absorbing the gluten particles sticking in ie perforations is further increased by the gluten lumps :ing pressed against the perforated plate by the scraper .ades. When leaving the feed end 6 of the trough the )ugh is still greasy due to its starch content and wet irface, and here it is even more important that scraper ades keep the perforations open, and therefore such :rapers 18 have to be fastened to the shaft 1 also where irring rods are fastened. The scrapers are suitably artnged in an angle of about 90 to the nearest stirring ads so as not to interfere with the stirring and tearing :tion of the stirring rods. The scrapers 18 are very lportant for a troublefree function of the device. The rapers 18 are connected to the shaft 1 by means of )nnecting rods 19 bent to the form of an are where all rrts of the are are situated in front of the scraper blade I in relation to the direction of rotation shown by the 'row 20. This shape of the connecting rods prevents re gluten lumps from sliding along the rods down to the raft 1 and twisting around the shaft and makes them fall f between the shaft 1 and the trough sides. Sabre-like treatment means 21 are also fastened to .e shaft 1. The edge 22 of the sabres 21 is facing the micircular bottom of the trough and runs at an angle the shaft 1, the main planes of the sabres forming 1 acute angle to the curve of the bottom of the trough The sabres 21 may be fitted both in the perforated ctions 14 and the imperforate sections 16. The mode of aeration of the sabres 21 is entriely different from that f the scrapers 18, in that the sabres partly cut and partly nch the gluten lumps between the edge and troughbottom 14 and 16, thus shredding the gluten lumps so that the lumps are opened and better exposed to the wash liquid, the result being that starch granules embedded in the lumps are uncovered and can be washed away from the gluten. The combined action of the scrapers 18 and the sabres 21 increases the eificiency of the treatment of the gluten and the dough. Tests have proved that this combined action of the scrapers 18 and the sabres 21, each with a different mode of operation, is of the utmost importance to the utilization of the invention. As the sabres 21 out large gluten lumps into smaller pieces, the lumps are reduced to a size suitable for the treatment in the trough. It is of advantage if the treatment means 18 and 21 are adjustable along the shaft 1 as Well as at an angle in relation to each other.

The trough 3 is preferably divided into compartments by means of dividing walls 23 over which the gluten lumps are lifted by means of the treatment means. The trough may be covered with lids 26 and mounted on legs 27.

The principle of the invention is not confined only to what is described above, but may be embodied in various forms within the scope of the appended claims.

What is claimed is:

1. Apparatus for washing treatment of a wheat flour dough to effect separation of starch from the gluten thereof while exposed to a washing liquid, said apparatus comprising in combination:

(a) an elongated treatment tank having inlet means and outlet means at opposite ends thereof, and having lower walls, and [opposite] side and end walls;

(b) said tank further comprising an elongated upwardly open trough fabricated with a generally semicircular [lower] trough bottom wall [having an imperforate portion opposite said inlet means of the tank] and said trough being at least partially Well perforated throughout [the rest of] its length to the outlet means of said tank;

(0) means supporting said trough in spaced relation [inwardly above] relative to the tanks lower walls;

((1) a rotatable shaft extending lengthwise of and within said trough and means rotatably supporting same in the end walls of said tank;

(e) said shaft having a plurality of axially [and successively alternately] spaced, different forms of treatment means extending radially from said shaft and extending [closely] adjacent to the semi-circular portions of said trough, said treatment means serving to repeatedly stir-and-tear the dough into lumps, scrape and collect, and shred and cut [flatten] the lumps of dough while moving it through the tank from the inlet to the outlet thereof; said treatment means including:

(1) [a first plurality of] at least one stirringand-cutting means for the initial tearing of the dough into lumps, and disposed on said shaft near the inlet end of said tank;

(2) a [second] plurality of axially spaced scraping-and-collecting paddle means [of a form substantially different] separate from said first mentioned stirring-and-cutting means, said [second] plurality of means disposed on said shaft commencing beyond said first-mentioned [plurality] means and extending thereafter in an axially spaced manner throughout the remaining length to the outlet end of said tank to repeatedly scrape, lift and collect said dough lumps; said paddle means including a generally planar blade portion having their outer edges facing to substantially engage essentially with perforated portions of said trough to perform as aforesaid, and

{3) a [third] difierertt plurality of doughshredding-and-[flattening] cutting means including [multi-armed, arcuate,] sabre-like members attached to the shaft at interspersed intervals with said second-mentioned [plurality] means above; [and] (f) [pipe] means associated with said tank for introducing wash liquid to the interior thereof, and including [elongated pipe means throughout an upper portion of the tank, said elongated pipe means including] outlet[s] means to direct a substantial wash spray toward said dough being treated throughout said tank;[.]; and

(g) means for draining said wash liquid from said tank to preclude undesirable buildup of said liquid in said trough.

[2. Apparatus as defined in claim 1 further including means for collecting, draining and positively discharging the wash liquid from said tank to preclude undesirable buildup thereof within said tank and trough] 3. Apparatus as defined in claim 1 wherein the said first [plurality of] mentioned stirring-and-cutting means includes diametrically opposed radial arms or blades, with the planes of said blades being angularly pitched relative to the axis of said shaft, and said blades being alternately disposed at 90 intervals with respect to the corresponding blades of [the] any adjacently spaced ones.

4. Apparatus as defined in claim 1 further including [wherein the] radial arms for supporting said paddle[s are] means, said arms being arcuately curved and disposed rotationally in front of said paddle scrapping blades in relation to its direction of rotation, said arcuate arms and disposition thereof thereby preventing lumps of gluten and dough from sliding down said arms and entangling around the rotating shaft, thereby making said lumps or dough fall off and drop between the shaft and trough side walls.

5. Apparatus as defined in claim 1 wherein the trough is provided with predetermined axially spaced imperforate sections interrupting the perforated portions.

6. Apparatus as defined in claim 1 wherein the trough is provided with predetermined axially spaced imperforate sections interruping the perforated portions, and said trough including relatively low arcuate, radial partition means disposed adjacent the aforesaid imperforate sections along the lower portion of said trough to divide said trough into predetermined zones, and including means for collecting, draining and positively discharging the wash liquid from said zones [tank] to preclude undesirable buildup thereof Within said tank and trough.

7. Apparatus as defined in claim 1 wherein said sabrelike members of paragraph (e) (3) [the third plurality means] each include [triple] circumferentially spaced generally planar [arms] blades having arcuate outer peripheral edges of which a substantial part of said edge essentially engages closely adjacent the lower trough walls to repeatedly shred[, spread or flatten and otherwise] and cut to break up the lumps to facilitate the separation of starch from gluten thereof; and the [triple arms] blades of each of said members having the plane thereof disposed [at respectively dilferent angles to each other] in a general propeller fashion to help collect and convey said dough lumps through said tank toward the outlet end thereof.

8. Apparatus as defined in claim 1 wherein said trough includes relatively low arcuate, radial partition means disposed to divide said trough and tank into predetermined zones, and including means for draining and discharging the wash liquid from said zones to preclude undesirable buildup thereof within said tank and trough.

References Cited The following references, cited by the Examiner, are of record in the patented file of this patent or the original patent.

UNITED STATES PATENTS MORRIS O. WOLK,

S. MA-RANTZ, Assistant Examiner Primary Examiner US. Cl. X.-R. 

